1. Field of the Invention
The present invention relates to a substrate processing apparatus.
2. Description of the Prior Art
For example, in a substrate processing apparatus, a wafer is sequentially carried along a load port, a loadlock chamber, a carrying chamber, and a process chamber, and is then processed in the process chamber.
Process chambers are separate spaces shielded by using gate valves, and wafers can be individually processed in the respective process chambers.
Generally, when a processing process is performed on substrate holding stages, only one wafer is processed in each chamber. Patent Document 1 discloses a technique necessary, in the case where non-processed wafers are sequentially carried to process chambers and processed wafers are carried from the respective process chambers to substrate supporters, for replacing a processed wafer with the next wafer to be processed.
[Patent Document 1] Japanese Unexamined Patent Application Publication No. 2006-86180
A conventional substrate processing apparatus includes two loadlock chambers configured to be stocked with wafers, a carrying chamber having a robot configured to transfer wafers to respective chambers, and two process chambers configured to process wafers therein. However, with this structure of the substrate processing apparatus, it is difficult to obtain a throughput higher than 200 wafers per hour. When it is intended to improve the throughput, the intention can be simply accomplished by adding process chambers around the carrying chamber. In this case, however, the size of the transfer robot disposed in the carrying chamber is relatively increased, and moreover the footprint of the substrate processing apparatus is inevitably increased due to the addition of process chambers.